title: The role of resistance and aerobic exercise training on insulin sensitivity measures in STZ-induced Type 1 diabetic rodents.
abstract: Individuals with Type 1 Diabetes Mellitus (T1DM) can develop insulin resistance. Regular exercise may improve insulin resistance partially through increased expression of skeletal muscle GLUT4 content.
  
  
  OBJECTIVE
  To examine if different exercise training modalities can alter glucose tolerance through changes in skeletal muscle GLUT4 content in T1DM rats.
  
  
  METHODS
  Fifty rats were divided into 5 groups; control, diabetic control, diabetic resistance exercised, and diabetic high and low intensity treadmill exercised. Diabetes was induced using multiple low dose Streptozotocin (20 mg/kg/day) injections and blood glucose concentrations were maintained moderately hyperglycemic through subcutaneous insulin pellets. Resistance trained rats climbed a ladder with incremental loads, while treadmill trained rats ran on a treadmill at 27 or 15 m/min, respectively, all for 6 weeks.
  
  
  RESULTS
  At weeks 3 and 6, area under the curve measurements following an intravenous glucose tolerance test (AUC-IVGTT) in all diabetic groups were higher than control rats (p<0.05). At 6 weeks, all exercise groups had significantly lower AUC-IVGTT values than diabetic control animals (p<0.05). Treadmill trained rats had the lowest insulin dose requirement of the T1DM rats and the greatest reduction in insulin dosage was evident in high intensity treadmill exercise. Concomitant with improvements in glucose handling improvements, tissue-specific elevations in GLUT4 content were demonstrated in both red and white portions of vastus lateralis and gastrocnemius muscles, suggesting that glucose handling capacity was altered in the skeletal muscle of exercised T1DM rats.
  
  
  CONCLUSIONS
  These results suggest that, while all exercise modalities can improve glucose tolerance, each mode leads to differential improvements in insulin requirements and protein content alterations.
authors.affiliation: Health and Rehabilitation Sciences, University of Western Ontario, London, Ontario, Canada.
authors.forename: Katharine E
authors.initials: KE
authors.lastname: Hall
authors.forename: Matthew W
authors.initials: MW
authors.lastname: McDonald
authors.forename: Kenneth N
authors.initials: KN
authors.lastname: Grisé
authors.forename: Oscar A
authors.initials: OA
authors.lastname: Campos
authors.forename: Earl G
authors.initials: EG
authors.lastname: Noble
authors.forename: C W James
authors.initials: CW
authors.lastname: Melling
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D003921:Diabetes Mellitus, Experimental / Q000097:blood* / Q000139:chemically induced / Q000378:metabolism / Q000503:physiopathology; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000139:chemically induced / Q000378:metabolism / Q000503:physiopathology*; D005951:Glucose Tolerance Test / Q000379:methods; D051275:Glucose Transporter Type 4 / Q000378:metabolism; D007328:Insulin / Q000097:blood* / Q000378:metabolism; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism / Q000503:physiopathology; D010805:Physical Conditioning, Animal / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D055070:Resistance Training / Q000379:methods; D013311:Streptozocin / Q000494:pharmacology*
chemical_list: D001786:Blood Glucose; D051275:Glucose Transporter Type 4; D007328:Insulin; C495694:Slc2a4 protein, rat; D013311:Streptozocin
keywords: ANOVA; AUC; Aerobic training; Analysis of variance; Area under the curve; C; CD; CHD; Coronary heart disease; DH; DL; DR; Diabetic high intensity aerobic exercise; Diabetic low intensity aerobic exercise; Diabetic resistance exercise; Diabetic sedentary control; GLUT4; GLUT4 protein content; HOMA; HbA1(c); Hemoglobin A1(C); Homeostatic model assessment; IVGTT; Insulin dose; Insulin resistance; Intravenous glucose tolerance test; Non-diabetic sedentary control; Plasma membrane glucose transporter 4; RG; RV; Red gastrocnemius; Red vastus lateralis; Resistance training; STZ; Streptozotocin; T1DM; T2DM; TBS; Tris buffered saline; Type 1 diabetes mellitus; Type 2 diabetes mellitus; WG; WV; White gastrocnemius; White vastus lateralis